<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
		<style>
			body,html{
				width: 100%;
				height: 100%;
				margin: 0;
			}
			.automargin{
				height: 100%;	
				display: flex;
			}
			.automargin div{
				margin-top: auto;/*试试margin-left: auto;吧*/
			}
		</style>
	</head>
	<body>
		<div class="automargin">
			<div>
				<img src="img/icon.png"/>
			</div>
		</div>
	</body>
</html>
